RouterOS reinstallation

I’ve just purchased a routerboard 333 for testing and I was simply planning on flashing it with OpenWRT or a Debian image. After further reading on RouterOS, I want to go ahead and evaluate it for this project as well.

My question is: can I flash the routerboard with a different image, and then flash back to RouterOS without any licensing troubles? Do I need to back up the image or license information before I overwrite the flash?

This is a valid question, from that standpoint, I need to completely re-flash our RB133c’s to install a clean copy of ROS. Our last shipment of RB133c’s have been branded in the ROS (log on and see another company name not MIKROTIK etc). And wont work properly, I am sure that if it had a clean not altered ROS firmware on these devices they work work as flawlessly as the rest of our ROS boxes.